Power carving tool

Abstract

A power carving tool has a housing, a driving motor, a cam shaft engaged with the rotary shaft of the driving motor and having a cooling fan, a cam sleeve with a slanted cam surface, engaged with the cam shaft and reliably held by a ball bearing supported by the housing, and an output shaft moved reciprocatingly by bringing a contact portion provided at the rear portion thereof into contact with the cam surface thereby to maintain a stable rotation of the cam sleeve and to avoid mechanical loss.

What is claimed is: 
     
       1. A power carving tool, which comprises: a) a housing in which a ball bearing is supported;   b) a rotary driving device;   c) a cam shaft which is engaged with a driving shaft of the rotary driving device so as to be rotated together with the driving shaft;   d) a cam sleeve which is rotated with the cam shaft, which is inserted into an inner ring of the ball bearing as to be rotated together with the inner ring, and which has, at a front face thereof, a cam surface; and   e) an output shaft which is disposed in such a manner that an axis of the output shaft is deviated from an axis of a united rotary driving shaft comprising the driving shaft of the rotary driving device, the cam shaft and the cam sleeve, wherein the output shaft has, at a rear end thereof, a contact portion for contacting the cam surface to be moved reciprocatingly in accordance with rotation of the united rotary driving shaft, and holds detachably a carving cutter at a front end thereof.   
     
     
       2. A power carving tool according to claim 1, wherein a cooling fan for cooling the rotary driving device is provided on the cam shaft between the ball bearing and the rotary driving device. 
     
     
       3. A power carving tool according to claim 2, wherein the cooling fan is formed separately from the cam shaft, and the cooling fan is fixed to an outer surface of the cam shaft so that a hub portion of the cooling fan is forced onto the outer surface of the cam shaft. 
     
     
       4. A power carving tool according to claim 2, wherein the cooling fan is integrally formed with the cam shaft. 
     
     
       5. A power carving tool according to claim 1, wherein the cam shaft has, at an outer surface thereof, a plurality of projections for engaging a plurality of recesses provided at a rear edge of the cam sleeve. 
     
     
       6. A power carving tool according to claim 5, wherein the cam sleeve has, at a front outer surface thereof, a flange abutting against a front face of the inner ring of the ball bearing, a stop ring being provided on an engaging outer surface between the projections of the cam shaft and the recesses of the cam sleeve to prevent the cam sleeve from coming out of the cam shaft, a spacer ring being provided between a rear face of the inner ring of the ball bearing and the stop ring to prevent the cam sleeve from moving with respect to the ball bearing. 
     
     
       7. A power carving tool according to claim 5, wherein the cam sleeve has, at a front outer surface thereof, a flange abutting against a front face of the inner ring of the ball bearing, part of the projections being extended outwardly so as to abut against a rear face of the inner ring of the ball bearing, a stop ring being provided on an engaging outer surface between the projections of the cam shaft and the recesses of the cam sleeve. 
     
     
       8. A power carving tool according to claim 1, wherein the cam sleeve has, at a front outer surface thereof, a flange abutting against a front face of the inner ring of the ball bearing, a stop ring being provided on a rear outer surface of the cam sleeve to hold the inner ring of the ball bearing between the flange and the stop ring. 
     
     
       9. A power carving tool according to claim 1, wherein the cam shaft is made from resin as an insulating material. 
     
     
       10. A power carving tool according to claim 1, wherein the contact portion of the outer shaft comprises a steel ball accommodated in a recess provided in a rear face of the output shaft. 
     
     
       11. A power carving tool according to claim 10, wherein the output shaft is urged by an elastic member to a front direction thereof. 
     
     
       12. A power carving tool which comprises: a) a housing;   b) a rotary driving device;   c) a cam shaft which is engaged with a driving shaft of the rotary driving device so as to be rotated together with the driving shaft;   d) a cam sleeve which is rotated with the cam shaft, which is held by a ball bearing supported in the housing so as to be rotated together with an inner ring of the ball bearing, and which has, at a front face thereof, a cam surface; and   e) an output shaft which is disposed in such a manner that an axis of the output shaft is deviated from an axis of a united rotary driving shaft comprising the driving shaft of the rotary driving device, the cam shaft and the cam sleeve,   wherein the output shaft has, at a rear end thereof, a contact portion for contacting the cam surface to be moved reciprocatingly in accordance with rotation of the united rotary driving shaft, and holds detachably a carving cutter at a front end thereof,   wherein the cam shaft has, at an outer surface thereof, a plurality of projections for engaging a plurality of recesses provided at a rear edge of the cam sleeve, and   wherein the cam sleeve has, at a front outer surface thereof, a flange abutting against a front face of the inner ring of the ball bearing, a stop ring being provided on an engaging outer surface between the projections of the cam shaft and the recesses of the cam sleeve to prevent the cam sleeve from coming out of the cam shaft, a spacer ring being provided between a rear face of the inner ring of the ball bearing and the stop ring to prevent the cam sleeve from moving with respect to the ball bearing.   
     
     
       13. A power carving tool which comprises: a) a housing;   b) a rotary driving device;   c) a cam shaft which is engaged with a driving shaft of the rotary driving device so as to be rotated together with the driving shaft;   d) a cam sleeve which is rotated with the cam shaft, which is held by a ball bearing supported in the housing so as to be rotated together with an inner ring of the ball bearing, and which has, at a front face thereof, a cam surface; and   e) an output shaft which is disposed in such a manner that an axis of the output shaft is deviated from an axis of a united rotary driving shaft comprising the driving shaft of the rotary driving device, the cam shaft and the cam sleeve,   wherein the output shaft has, at a rear end thereof, a contact portion for contacting the cam surface to be moved reciprocatingly in accordance with rotation of the united rotary driving shaft, and holds detachably a carving cutter at a front end thereof,   wherein the cam shaft has, at an outer surface thereof, a plurality of projections for engaging a plurality of recesses provided at a rear edge of the cam sleeve, and   wherein the cam sleeve has, at a front outer surface thereof, a flange abutting against a front face of the inner ring of the ball bearing, part of the projections being extended outwardly so as to abut against a rear face of the inner ring of the ball bearing, a stop ring being provided on an engaging outer surface between the projections of the cam shaft and the recesses of the cam sleeve.